Closing multiple windows for a single process

Hi,

I am using SilkTest Workbench 15.5. And, my application under test is developed using WPF.

I have multiple windows opened for AUT (that is a single process in the task manager). I used the below code to kill the application for certain specific cases.

 Dim app_process() As Process = Process.GetProcessesByName("ADC.Plaftorm.UI.Host")

For Each proc As Process in app_process

     proc.Kill()

Next

When there is only a single window, the above code is working fine. But, when there are multiple windows opened then nothing is happening.

Could someone please help me in this?